I have been watching my plants carefully and have noticed something. I am not sure if it is normal or if it is a tell tale sign of something.

I notice that my H.Polysperma leaves look fine at night before lights out. When I check on the leaves during the morning, they still look fine with the tips pointing more or less straight up. But, when the lights come on at 2pm (CO2 on at 1pm), they droop straight down and only gradually start to pick up again after several hours.

By about 11pm at night, the leaves are starting to fold upwards, i.e. leaf tips pointing up towards the lights. This looks normal to me, like the leaves have indeed had their 'fill' for the day.

Next morning at around 8am they are still more or less pointing upwards, again, this looks ok to me. They continue to look like this, maybe gradually coming down a little bit, until the lights come on at 2.

Once the lights have been on for an hour or so, the leaf tips are pointing in the exact opposite direction - i.e. at the gravel!!! It is as though the leaves have all suddenly become limp! (will get a photo if my description still not clear?)

Another couple of hours goes by and they then come back up again and look 'normal'.

Could it be that when my lights come on at 2pm, even though I have had the CO2 on since 1pm, that the CO2 levels are suddenly being reduced very rapidly by the CO2 starved plants? Perhaps putting the CO2 on earlier or something is the key?

Lifetime Member

No, the description is clear enough, would just like to see a pic, that's all.

My c02 comes on about 90 minutes prior to lights on, but my leaves NEVER have pointed at the substrate....Many folk have the c02 come on early so that c02 levels are better for when the photoperiod begins........

The leaves pointing at the substrate is the abnormal thing IMO. I have never seen this behavior.

All stem plants that I have kept open/close their leaves on a daily basis as you describe.

It is the pointing down that is interesting.

Is it a new plant and not yet established? Could the petiole be weak and is causing the 'droop'?

Is it in an area that is low on current and/or c02? If you take a stem or two and move it to a different area, does it behave the same?

Is it a new plant and not yet established? Could the petiole be weak and is causing the 'droop'?

Is it in an area that is low on current and/or c02? If you take a stem or two and move it to a different area, does it behave the same?

Click to expand...

It's not a new plant - been in the tank for a couple of months now. Originally I was having a problem with just the cuttings doing this, but much worse, in that the cuttings would disintegrate completely, but I added more CO2 and that seems to have sorted that issue out.

The plant is not in an area of low current - the leaves are swaying in the current and the tank looks like a glass of champagne! CO2 is fed directly into the intake of a powerhead which is blasting the mist all over the tank and is circulating it well.

I haven't tried moving a stem or two to a different location, but I suppose this would be worth a try.

I have turned up the CO2 even more - I'll post a seperate thread about this as I have some additional questions.

Regarding this issue - could is simply be that the CO2 is more stable than it originally was when the plants were disintegrating completely, but still not quite stable enough? As Tom suggests, the closer I get to 30ppm the more 'wiggle' room I'll have.

I am not sure that your Hygro is a CO2 problem, not all the leaves are drooping, either. It looks like it has large leaves and reasonably healthy. I have found H. Polysperma to be a weed of epic proportions to the point that I had to tear it all out because it was too much to maintain. Increasing the CO2 will likely help the algae issue but also drive mad growth of the H. Polysperma.

You may be able to more quickly resolve the algae issue by adding flourish excel at the recommended dosages. Still it takes time for conditions to improve. Once you have the CO2 steady for conditions to improve you really need give it two to three weeks, with good CO2, EI, water changes, maintenance, etc.

I'm really wondering whether this is a CO2 problem. The CO2 level in my tank *must* be high enough now. If I turn it up just slightly more the fish start gasping - the point at which fish start gasping is higher than the maximum amount of CO2 that plants can use, so, there must be *plenty* of CO2 in the water.

I'm not using a drop checker or doing water tests or anything here - just simple observation and logic.

My water circulation is good also, as I have a large powerhead causing the plant leaves to move about.

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